Signor to thomas james montgomery



(No Model.)

J. W. SWAN.

MANUFACTURE OF GARBONS FOR INGANDESGENT LAMPS. N 0. 322- Patented July 28, 1885.

N. PETERS. Phulwlilhcgnpher, Wishlngtcn, D. c.

UNITED STATES PATENT OFFICE.

JOSEPH XVILSON SXVAN, OF BROMLEY, COUNTY OF KENT, ENGLAND, AS- SIGNOR TO THOMAS JAMES MONTGOMERY, OF NEW YORK, N. Y.

MANUFACTURE OF CARBONS FOR INCANDESCEN T LAMP S.

EAPECIPICATION forming part of Letters Patent No. 322,993, dated July 28, 1885.

Application filed August 7, 1884. No model.) Patented in England December 31. 1883, No. 5,978; in France April 28, 1884, No. 161,780, and in Germany May 4, 1884, N0. 30,29].

To aZZ whom it may concern:

Be it known that I, JOSEPH WILsoN SWAN, chemist, a subject of the Queen of Great Britain and Ireland, and residing at Bromley, in the county of Kent, England, have invented certain Improvements in the Manufacture of Oarbons for Incandescent Electric Lamps, (for which I have obtained patents in Great Britain, No. 5,978, dated December 31, 1883, in France, dated April 28, 1884, and in Germany, dated May 4, 1884,) of which the following is a specification.

It is necessary, for obtaining the greatest efficiency in electrical lamps in which light is produced by the incandescence of a carbon filament or thread, that the filament or thread should be of a homogeneous and solid texture, and that its section should be uniform in size.

Hitherto great difficnlty has been experienced in producing thin carbon filaments or threads of a perfectly uniform sectional size and at the same time homogeneous and solid in texture.

My invention has for its object the production of carbon filaments or threads possessing these qualities and the removal of the difficulties which have hitherto stood in the way of their manufacture.

According to my said invention I take a carbonizable material, of the nature hereinafter mentioned, in aplastic or semi-liquid state, and I squeeze or press it through a hole or holes or die or dies, so as to form a filament or thread or filaments or threads of any required length and of equal substance throughout its or their length, and also of any required form in transverse section.

The material I employ in carrying out my invention is a solution of nitro-cellulose in acetic acid or other solvent. Other carbonizable material may be combined with the nitro cellulose, or the nitro cellulose solution may be used alone; or I employ nitroglucose rendered plastic by heat. I project the filament or filaments or thread or threads as it or they issues or issue from the die into a liquid, such as alcohol, of from seventy to eighty per cent., or into other liquid which has the effect of setting or giving coherence to the issuing thread.

The accompanying drawings represent an apparatus which may be used in carrying my invention into effect.

tion perfectly understood; but I do not limit myself to the use of this particular form of apparatus.

Figurel is an elevation, and Fig. 2 is a vertical section.

A represents a strong metallic cylinder, constituting the body of the apparatus. It is closed by a covering-piece, B, held down by the cap-piece G, which is screwed down so as to compress the packing D firmly to give a tight joint. E is a pipe from the reservoir oi' an air'compressing pump secured in the nozzle-piece F, through which the pa-ssageG- lead to the interior of the part A, which is lined with a glass cylinder, H, terminating in a nippie-piece, h, having a fine orifice therethrough.

and passing through the bottom of the part A. I is a lining of plaster-of-paris, to keep the glass cylinder H in place. J is a screw closing plug or tap, by which the passage G can be closed while the air is being compressed by the pump attached to the pipe E.

The apparatus may be supported by a stand, as at K, so that the outlet'orifi ce through the nozzle his situated over avessel, L, into which the material is passed as it issues from the said orifice. The carbonizable material, in a plastic or semi-liquid state, is put into the receiver A, which is firmly closed. The tap J is closed, and air is pumped into the reservoir of the pump until it has attained a sufficient pressure, when the top J is opened and the carbonizable material is forced slowly through the orifice in the nozzle h, from which it may pass into the vessel L, containing a liquid tor the purpose hereinafter described;

When the threads or filaments have been formed in the manner described, I treat them with a solution of hydrosulphate of ammonia or other equivalent deoxidizing agent until they are no longer in a condition to bn rn explosivel y, and I then dry them and sh apie them into the forms in which they are to be i' sed in the lamps; and I carbonize them in any suitable manner.

I am aware that it has been proposed to It is given as an ex ample and as a means of making the invenmake filaments for incandescent lamps by placing plastic carbonizable substance within,

a receptacle and forcing it therefrom through a die, forming filaments, which are cut into lengths and carbonized; also, that it has been proposed to make carbons as follows: treating cellulose with a-mixture of sulphuric and nitric acids producing pyroxyline, dissolving this by a suitable solvent, and treating the product with ammonium sulphide or equivalent agent; also, by dissolving fibrous cellulose, forming the solution into sheets from which the impurities are removed and the sheets then cut into filaments and carbonized; also, by dis solving cellulose by a suitable solvent and forming the solution into sheets, or subjecting it to heat and pressure and forcing it through (lies to form a filament, and hence I make no claim to such process.

I claim- 1. In the process of manufacturing carbons for incandescent electric lamps, the following steps: placing a mixture or solution of nitro cellulose in acetic acid (or other solvent) in a receiver and forcing said mixture through a contracted opening, thereby producing a filament and conducting said filament into aliquid for hardening the same and subsequently carbonizin g the filament, substantially as set forth.

2. Manufacturing carbons for incandescent electric lamps by forcing a mixture or solution of nitro-ccllulose in acetic acid (or'other solvent) or the equivalent thereof, hereinbefore stated, through a hole or holes or die or dies and into a liquid for causing the setting, coagulation, or coherence of the issuing filamentor filaments, and subsequently treating the said filament or filaments with a deoxidizing agent and then carbonizing the said filament or filaments, substantially as hereinbefore described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOSEPH XVILSON SW'AN. \Vitnesses:

WM. JonN Wnmrs, G. Woonnow,

Both-0f 31 Lombard Street, London. 

